Tunnel fans are used for ventilation and smoke extraction in the road and train traffic tunnels. "Jet fans" use impulse technology to move air through the tunnels in a longitudinal direction. Some system designs have also used temperature-resistant axial fans for replacement and/or exhaust air. Tunnel fans have low construction costs and enable more efficient use of space compared to ducted solutions.
ETS NORD tunnel fans are available in uni- and reversible versions, and they are usually equipped with silencers. Fan solutions are available in either square or traditional round models. The square fan saves space in terms of height, which means that not as much space needs to be allocated for the technology in the tunnel ceiling compared to round fans. The thrust forces of the fans are between 105 and 3,002 N, the nominal power is between 2.2 and 90 kW, and the sound pressure levels are between 80 and 106 dB (A). The basic material of the fans is galvanized steel and optionally stainless steel. All tunnel fans are given the standard EN 12101 part 3, 200 ° C, 300 ° C or 400 ° C./h.